Roof rail seal questions

I ordered the foam tape that goes between the roof and the spent some time today cleaning the 1972 adhesive and foam remains from the moldings. What on earth dissolves it? Acetone helped a little and even MEK didn't do much. Heat just made a gummy mess. I ended up scraping off as much as I could, and carefully wire-wheeling off most of the rest.

From the mess it appears that the tape was adhered to the molding, not to the roof. Or is it double-sided-sticky tape? Will find out when it arrives I guess. Does it matter which side it's stuck to?